tasmād ajñāna-sambhūtaḿ
hṛt-sthaḿ jñānāsinātmanaḥ
chittvainaḿ saḿśayaḿ yogam
ātiṣṭhottiṣṭha bhārata

Translation of Bhagavad Gita 4.42

Therefore the doubts which have arisen in your heart out of ignorance should be slashed by the weapon of knowledge. Armed with yoga, O Bharata, stand and fight.

Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:

The yoga system instructed in this chapter is called sanatana-yoga, or eternal activities performed by the living entity. This yoga has two divisions of sacrificial actions: one is called sacrifice of one’s material possessions, and the other is called knowledge of self, which is pure spiritual activity. If sacrifice of one’s material possessions is not dovetailed for spiritual realization, then such sacrifice becomes material. But one who performs such sacrifices with a spiritual objective, or in devotional service, makes a perfect sacrifice. When we come to spiritual activities, we find that these are also divided into two: namely, understanding of one’s own self (or one’s constitutional position), and the truth regarding the Supreme Personality of Godhead. One who follows the path of Bhagavad-gita as it is can very easily understand these two important divisions of spiritual knowledge. For him there is no difficulty in obtaining perfect knowledge of the self as part and parcel of the Lord. And such understanding is beneficial, for such a person can easily understand the transcendental activities of the Lord. In the beginning of this chapter, the transcendental activities of the Lord were discussed by the Supreme Lord Himself. One who does not understand the instructions of the Gita is faithless, and is to be considered to be misusing the fragmental independence awarded to him by the Lord. In spite of such instructions, one who does not understand the real nature of the Lord as the eternal, blissful, all-knowing Personality of Godhead is certainly fool number one. Ignorance can be removed by gradual acceptance of the principles of Krishna consciousness. Krishna consciousness is awakened by different types of sacrifices to the demigods, sacrifice to Brahman, sacrifice in celibacy, in household life, in controlling the senses, in practicing mystic yoga, in penance, in forgoing material possessions, in studying the Vedas, and in partaking of the social institution called varnashrama-dharma. All of these are known as sacrifice, and all of them are based on regulated action. But within all these activities, the important factor is self-realization. One who seeks that objective is the real student of Bhagavad-gita, but one who doubts the authority of Krishna falls back. One is therefore advised to study Bhagavad-gita, or any other scripture, under a bona fide spiritual master, with service and surrender. A bona fide spiritual master is in the disciplic succession from time eternal, and he does not deviate at all from the instructions of the Supreme Lord as they were imparted millions of years ago to the sun-god, from whom the instructions of Bhagavad-gita have come down to the earthly kingdom. One should, therefore, follow the path of Bhagavad-gita as it is expressed in the Gita itself and beware of self-interested people after personal aggrandizement who deviate others from the actual path. The Lord is definitely the supreme person, and His activities are transcendental. One who understands this is a liberated person from the very beginning of his study of Bhagavad-gita.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

This verse concludes. Cutting the doubts situated in the heart, taking shelter of niskama karma yoga, rise up in order to fight the battle. Having spoken of the various means of liberation, jnana is praised. But the means to jnana is karma. That has been pointed out in this chapter.

Commentary by Sri Ramanuja of Sri Sampradaya:

4.42 Therefore, after sundering this doubt concerning the self, born of beginningless ignorance and present in the heart, by the sword of the knowledge of the self in the manner explained before, practise the Karma Yoga taught by Me. For that, rise up, O Arjuna.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

Lord Krishna is instructing Arjuna to destroy all doubts arising from ignorance of the atma or soul and having discrimination between the soul and the body take refuge in karma yoga or the performance of prescribed Vedic activities which is the means to atma tattva or soul realisation.

I bow to the Supreme Lord Krishna, the destroyer of all doubts who has taught the dual faiths of karma yoga and jnana yoga or the cultivation of Vedic knowledge according to the natural attributes and qualifications among humans.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

Having explained the means of acquiring spiritual realisation and the disadvantages of achieving spiritual realisation the Supreme Lord Krishna concludes this chapter.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

The sword of spiritual knowledge is the eternal atma or soul. All doubt should be completely uprooted from one’s heart and mind and follow the path that Lord Krishna has so concisely explained which is first and foremost to do one’s duty in life according to qualification. Following this path one will acquire the spiritual knowledge to cross over samsara the cycle of birth and death and attain moksa liberation from material existence.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

4.42 Tasmat, therefore, O scion of the Bharata dynasty; atistha, take recourse to, i.e. undertake; yogam, yoga -performance of actions, which is a means to full Illumination; and now, uttistha, rise up for battle; chittva, cutting asunder; jnanasina, with the sword of Knowledge-Knowledge is full Illumination, which is a destroyer of such defects as sorrows, delusion, etc.; that itself is the sword; with that sword of Knowledge-;enam, this; samsayam, doubt; atmanah, of your own, which is a source of one’s own ruin and is most sinful; hrtstham, in the heart, residing in the intellect; ajnana-sambhutam, arising from ignorance, born of non-discrimination. The word atmanah is used because doubt concerns oneself. Indeed, another’s doubt cannot be removed by someone else. Hence the word ‘own’ is used. So, although the doubt is with regard to the Self, it is really one’s own.

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

4.42 Tasmat etc. Cutting asunder the doubt, you must practise, by the said method, the Yoga, the dexterity in action; and then stand up i.e., perform your activities simply with the idea that they are to be performed.

Sanskrit Shloka Without Transliteration Marks:

tasmad ajñana-sambhutam
hrt-stham jñanasinatmanah
chittvainam samsayam yogam
atisthottistha bharata

Sanskrit to English Word for Word Meanings:

tasmāt — therefore; ajñāna-sambhūtam — born of ignorance; hṛt-stham — situated in the heart; jñāna — of knowledge; asinā — by the weapon; ātmanaḥ — of the self; chittvā — cutting off; enam — this; saḿśayam — doubt; yogam — in yoga; ātiṣṭha — be situated; uttiṣṭha — stand up to fight; bhārata — O descendant of Bharata.